In the past, in such electronic apparatuses having image sensing functions as a digital still camera and a digital video camera, a solid-state image sensing device such as a charge coupled device (CCD) image sensor and a complementary metal oxide semiconductor (CMOS) image sensor has been used. The solid-state image sensing device has pixels each being a combination of a photo diode (PD) for photoelectrical conversion and two or more transistors, thereby providing an image on the basis of a pixel signal outputted from two or more pixels arranged on an image plane on which an image of a subject is formed.
Further, recently, a solid-state image sensing device on which phase difference detection pixels capable to detecting a phase difference in an image plane by a configuration in which a PD in one pixel is separated into two are installed has developed. This solid-state image sensing device can be used to independently read, at the time of auto focusing, electric charges generated in the two PDs of a phase difference detection pixel and use these charges as a phase difference detection signal for detecting the phase difference of an incident light, thereby controlling focusing. On the other hand, at the time of image sensing, the above-mentioned solid-state image sensing device can be used to simultaneously read the charges generated in the two PDs of a phase difference detection pixel so as to output a signal as one pixel, thereby providing an image as an image sensing signal.
As described above, the phase difference detecting pixel can output both a phase difference detection signal and an image sensing signal, thereby playing two roles at the same time. Therefore, switching between the roles of the phase difference detection pixel at the time of auto focusing and at the time of image sensing allows the use of not only a part of a solid-state image sensing device but also all the pixels as phase difference detection pixels.
Further, PTL 1 discloses a solid-state image sensing device in which a PD that receives the light in a wavelength range used for image sensing is not divided and a PD formed at a position deeper than the above-mentioned PD is pupil-divided for use in phase difference detection, thereby executing focusing by use of an infrared light that is photoelectrically converted in a domain deep in a semiconductor substrate.